An embodiment of an arrangement for enabling kissing balloons as is set forth in the opening paragraph is known from EP 1 369 097. In the known arrangement a balloon catheter assembly is provided having twin balloons adapted for treating bifurcated vessels. In the known system one or both balloons may be stepped to provide a proximal section, a distal section of larger diameter and a step between these two sections. In use, the twin balloons are positioned across the bifurcation so that the distal sections of the two balloons enter respectively the main and side branches distally of the bifurcation and the smaller diameter proximal sections are positioned side by side in the common area in the vessel proximally of the bifurcation.
It is a disadvantage of the known system that the said side by side positioning, although occasionally resulting in a common surface of the two balloons, is not reproducible. It will be further appreciated that in specific treatments of an abnormal bifurcated area, such as aneurism at bifurcation, a pre-defined and reproducible kissing surface of the two balloons is required.